Tracking device for trailers



Sept.. 1, 1925.

4 A. y. oHMAN TRACKING DEVICE FOR TRAILERS Filed July 9. -192:5

Patented Sept. 1, 1925.

UNITED STATES c intim ALBIN I. OIIMAN, OE EPI-IRAIM, WISCONSIN. i

i TRACKING DEVICE FUER TRAILERS.

Application led July 9,

To all whom t may concern.'

Be it known that I, ALBIN I. OHMAN, a citizen of thevUnited, States,residing at Ephraim, in the county of Door, State of Wisconsin, haveinvented certain new and useful Improvements in Tracking Devices forTrailers; and I do hereby declare the following to be a full, clear,a-nd enact `description of the invention, such as will enable others`skilled in theart to which it `appertains to make and use the same,

This invention relates to new kand useful improvements inlsteeringmechanism and particularly to steering mechanisms for trailers.I

One object of the invention is to provide a steering mechanism of thischaracter by means of which thek trailer may be readily and accuratelysteered when the motor niachine is proceeding-1 either. forwardly orbackwardly. 'Y e Another object is to provide a device of this characterwhich is automatic yin its operation, and requires no manipulation oratA tention of the driver of the puller machine.

Another object is to providev a device of this character whichautomatically shifts for positive operation, when the pulling machinechanges its direction from for` ward to backward, and vice versa.

Other objects and advantages will be apparent from the followingdescription when Y taken in connection withv the accompanying drawings.

In the drawings Figure 1 is a plan view of the rear porl tion of amachine whichv is pulling, and the front portionof the trailer, showingthe application of the present invention.

Figure 2 is a plan view showing the change of direction toward theright, while proceeding forwardly. .Y n

Figure 3 is a plan ,view` showing the change of direction toward theright, while proceeding backwardly'.

Figure 4 is an enlarged section on the l line 4-'4 of Figure 1, lookingin the direc# tion of the arrows.

Figure 5is a vertical sectiony on the line 5-5of Figure 1, looking inthe direction of the arrows. v y i p Figure 6 is an enlarged sectionaldetail of a portion of one of the wheels showing the ring gear and thesegmental gear engaged therewith.

Referring particularly to the yaccompany- 1923. serial No. 650,375.

ing drawings, 10 represents the pulling inachine and 11 the trailer. Thepulling machine hasthe rear axle 12 to which is secured the bar 13, bymeans of the clamps 14, said bar being disposed in parallel relation totheaXle, and rearwardly thereof. Connected to the ends of the bar 13 arethe chains15 and 16, to which more particular reference will be madelater herein.

The trailer is represented as a whole by the numeral 11, and includes.the aXle 18, on the ends of which are pivotally mounted the steeringknuckles 19 and 20, 4respectively. To the outer face of each of theknuckles .is secured a disk 21 having an outwardly exw tendingperipheral iange 22, and extending through the center of the disk, andkof the knuckle casting is a circular socket 29 within which krotates agear wheel 30,

the shaft ofwhich extends through the disk 2l, at one side of the stub23, where it is provided with aA segmental gear 31. In the disk,concentrically with the shaft of the gear 31, is an arcuate slot 32, inwhich rides the lug 33 formed on the segmental gear, Slidable in thetubular member 27 is'a rod 34, the sameV having rack teeth 35 which areengaged with theV teeth of the gear 30, through an opening 36 formed Ainthe tubular member 27, and which opening is arranged abovethesaid socket29. The said disk 25 forms the central portion of the wheel 37, and hasthe inturned vperipheral flange 38 which is disposed inwardlyof theflange 22 of the disk 21. The flange 38 is formed with the internal gearteeth 39 which are arranged to'engage with the teeth of the segmentalvgear 31 to vrockthe same on its pivot and cause the rotation of theVshaft thereof, andl the driving of the rod 34 longitudinally throughthetubular member 27. Securedtorthe'` opposite ends of the rod 34 are thechain 15, beforeem'entioned, and the chain 40, the latter chain havingits other end connected with the chain 15 at a point a suitable distanceforwardly of the point of connection with the rod 34. CaraoL ried by thefront end of each of the tubular members 27 is a clip er1 which ispivotally connected to an end of the steering' tie rod 42, by means ofwhich both of the knuckles are caused to swing' in unison.

rlhe chain 16'has its other end secured to the forward end of the otherrod 311, or that rod which is carried by the knuckle 20. engraginf;around the pulley 28, while a chain 43, similar to the chain 40, isconnected to the other end of this other rod Se, and to the chain 16. ata point correspondine, to the point of attachment of the chain ll() withthe chain 15. Y

Connected to the center of the bar 13, by means of the ball and socketjoint 41A?, at one end, and at its other end to the axle 18 by means ofthe ball and socket joint 115, is the draw-bar 45, and by means of whichthe trailer is pulled.

Upon forward movement being' in'iparted to the trailer, the wheelsthereof rotate in the usual manner, but by reason of the teeth on thedisk 21 engaging' with the teeth. of the segmental gearrll, saidsegmental gear' will be rocked on its pivot, causing 'the gear 30 to berotated and the rods 234-. to be moved rearwardly through the tubularmembers 27, with the result that the chains 15 and 16 will be drawntaut, while the chains e() and 413 will be slackened. Upon the pulling`machine turning toward the right, as shown in Figure 2, the left-handend of the bar 13 will exert a pull on the chain 1G, which in turn pullson the forward end of the tubular member 27, and the rod 34, resultingin the swinging of the knuckle 20 and directing the wheels toward theoutside of the curve. Thus the trailer will properly track after thepulling machine. A turn to the left will cause the chain 15 to bepulled, and the wheels swung towardV the right, or toward the outside ofthe curve. lVhen the motor car is to proceed in the other direction,that is backwardly, to push the trailer, the wheels of the trailer will,of course, rotate in the opposite direction from that first described.Upon rotation of the trailer wheels, backwardly, the internal gear disks21 and 25 will pick up the segmental gears 31, and swing' them to theopposite ends of their paths of movement, which will cause the gears 30to slide the rods 311 forwardly whereby the chains L10 and 113 will bebrought into taut condition, while the portions of the chains 15 and 16,between the points ofattachment of the chains 40 and 43 therewith, andthe rollers 28, will be slackened. Upon the motor car' turning` towardthe right, the chain will be pulled, which will swing' the left-handknuckle 20,. cf the trailer, so that the wheels of the trailer will besteered toward the right, and the trailer pushed around the curved por--tion of the road, ahead of the motor car.

From the foregoing it will be readily seen that the trailer may beaccurately guided, both to track behind the motor car, and to more aheadthereof, in accordance with the direction of movement of the motor car.i*`urthermore, the chains will be automatically tightened and slackened,accordin to the direction of procedure of the motor car, therebyobviatinnf any attention on the part of the driver of the motor car.

Secured to the segmental rear 31 a leaf spring 4&7, which carries afriction member arranged to engage with the inner face of the disk 25,so that when the wheel, forming a. part of the disk, rotates, theswinging of the segmental gear, into mesh. with the internal or ringgear ofthe disk, will be assured.

lVhat is claimed is:

1. In a trailer steering; mechanism, a propelling car, a trailer car.draft connections between the cars, dirigible wheels on the trailer car,flexible connections between the propelling' car and the dirin'iblewheels, and means operable by the said wheels for tightening' certain ofthe flexible connections and loosening certain others of saidconnections whereby to steer the said wheels in forwardly or backwardlydirections.

2. ln a trailer steering mechanism, a propelling car, a trailer car,draft connections between the cars. dirigible wheels on the trailer car,slidableV elements mounted adj acent and movable with the said wheelsupon steering' thereof, flexible elements connected to the ends of theslidable elements and to the propelling' car, flexible elements connect'ed to the slidable elements and to the first flexible elements, andmeans operable by the rotation of said wheels for tightening' certain ofthe flexible elements and loosening' certain of the flexible elementswhereby to steer said wheels upon movement of the propellinn carbackwardly and forwardly.

3. In a trailer steering mechanism` a propolling:- car, a trailer car,draft connections between the cars, knuckles on the trailer car. wheelson the knuckles, slidable elements on the knuckles, flexible elementsconnected to the slidable elements and to the propelling` car, flexibleelements connected to the slidable elements and to the first flexibleelements, and means operable by the rotation of the said wheels foradjusting' the flexible elements to steer the knuckles upon movement ofthe propelling` 'ai' 'forwardly or backwardly. n

et. In a trailer steering' mechanism, a propelling; car, a trailer car,dra-ft connections etween the cars, steering knuckles on the trailercar, wh eels rotatably supported on the knuckles. slidable rods mountedon the knuckles, a chain connected to each of the rods and to thepropelling' car, a second chain connected to a rod and to the firstConnected to the other ends of the lrods and to lthe firstchans, a gear`carriedhy each i knuckle and operatively engaged with a rod a segmentalgear carriedloy the lirst gear3 a ring gear on a Wheel for movingengagement With a segmental gear to slide a rod and thereby tightencertain `chains and loosen others, and means on the segmental gear A:forfrictional `engagement With the Wheel for causing the engagement of the`segmental gear with the ring gear.

In testimony whereof, I aiiX my signature.

ALBIN I. OHMAN.

